1. Field of the Invention
This invention relates to a total knee arthroplasty (TKA) system, in particular a TKA system that includes a universal cutting jig for shaping the distal femur and a multitude of TKA prosthesis designs that fit into the same shaped distal femur.
2. Description of Related Art
The TKA systems typically have a distinct profile to the distal femur integrating a surface specific to the system. This profile can be the same for the different sizes in a system, but typically is not the same for different articulating surface designs. Attempts to create cutting jigs and methods for shaping the distal femur are previously described. Lacey (U.S. Pat. No. 4,502,483) discloses a method for resecting and shaping the distal femur through the use of a cutting jig is a standard practice for preparing the femur. The method described by Lacey (U.S. Pat. No. 4,502,483) is incorporated by reference in its entirety. Russell et al. (U.S. Pat. No. 4,722,330) and Axelson et al. (U.S. Pat. No. 6,558,391) disclose a similar method for resecting and shaping the distal femur with various cutting jig designs specifically for receiving a knee prosthesis. Russell et al. (U.S. Pat. No. 4,722,330) and Axelson et al. (U.S. Pat. No. 6,558,391) are incorporated by reference in their entirety. The cutting jigs described in the aforementioned prior art addresses the need to shape the femur and the shaped profile is specific to a single TKA system design. The system specific profile requires that a specific set of instrumentation, including a cutting jig for shaping the distal femur, be provided. The specificity of the instruments to a TKA system limits the usage of the instrument set solely to one TKA design.
The methods and systems described by Lacey, Russel, and Axelson do not address the need for multiple TKA femoral component designs for a given shaped profile. The specificity of the cutting jig to a specific TKA system design requires multiple sets of instruments if more than one TKA system design is used by a particular surgeon. It is common for a surgeon to use several designs, as patients anatomies, pathologies, and lifestyles may dictate the need for a wide range of motions that no single TKA system design can provide.
Gerbec et al. (U.S. Pat. No. 6,866,683) discloses a modular TKA system that offers multiple designs with respect to the portion of the implant that integrates with the patients' bone. However, the design describes only one articulating shape profile, and the modular nature of the system is to allow for use of this system for primary or revision TKA. This system does not allow for flexibility with articulating surface profile. Furthermore, complex modular systems may be less desirable due to their inherent complexity and the increased number of regions or components that can each increase the risk for implant failure.
A general overview of the history of TKA systems can be found in Robinson, “The Early Innovators of Today's Resurfacing Condylar Knees,” The Journal of Arthroplasty, Volume 20, Number 1 Supplement 1 2005, pages 2-26.
There is a need in the art for a TKA system that utilizes a universal cutting jig for a variety of TKA articulating profile designs. A system that solves this need will reduce the amount of instrumentation required for multiple TKA designs and will provide surgeons with more choices of TKA profiles for a given surgery.